[GRASSLIST:794] Re: Fwd: slope map,watershed

[Ramin Safa]

Hi
Thanks for your reply
if you have a GRASS BOOK ,in page 179:
Let me know ,how can i create like this area:it has a
border :but not for precipitatation,for slope ,and basine
and the other map assotioated it(watershed).
By r.mapcalc: can i creat it?or no.?
Regards 
Ramin
--- Massimiliano Cannata
<massimiliano.cannata at ist.supsi.ch> wrote:
> I'm not sure to have understand all, but:
> 
> 1- a raster map is a "box" rappresentation, in fact in a
> raster
> ascii you have an header that says the coordinate
> extention of your
> "box" (or better to say region). So you cannot have any
> border on
> it.
> 
> 2- when you intepolate you will always have some border
> problem,
> that's because on your border (note, the border of your
> interpolated set of line or point) you have only one side
> value,
> while on the other you have null value so you begin to
> invent....
> it's usually done to keep a larger area and then take off
> a buffer.
> 
> 3- if you want to have a raster with your value only
> inside the
> watershed consider to interpolate, calculate slope and
> after assign
> a null value outside you interest region. I f you can
> create a
> raster that works as a mask (for example with value=1
> inside your
> watershed and value=0 outside) you can easly do it with
> r.mapcalc.
> 
> 
> Ramin Safa wrote:
> 
> > Hi
> > Regarding folowing email
> > My area is a watershed but:
> > I don want to do r.watershed
> > I need to use only my area(watershed ) not a
> squer(whole
> > screen)and i need slope,,...
> > please if anybody knows ,help me
> > sincerely
> > Ramin
> >
> > Note: forwarded message attached.
> >
> > =====
> >
> > Ramin Safamanesh
> > Department of  Environment Science , UPM
> > Email :  rsafamanesh at hotmail.com Tel  :  0060122399448
> >
> > __________________________________
> > Do you Yahoo!?
> > Yahoo! SiteBuilder - Free, easy-to-use web site design
> software
> > http://sitebuilder.yahoo.com
> >
> >   --------------------------------------------------
> >
> > Subject: [GRASSLIST:781] slope map
> > Date: Mon, 21 Jul 2003 18:53:15 -0700 (PDT)
> > From: Ramin Safa <raminsafa at yahoo.com>
> > To: mlennert at club.worldonline.be, grasslist at baylor.edu
> >
> > hi
> > *Regarding slope map(raster),befor v.to.rast my map had
> a
> >   border but after v.to.rast  ..the border is
> disapeared
> > and **because of this when i run : r.slop.aspect
> ....slope
> > map
> >    and aspect map and .. will be wrong, am i right or
> no?
> > ***if this is true how i save the border and if it is
> not
> >
> >    true how i solve my problem?
> > ****and also if i run v.surf.rst or r.surf contour i
> have
> >    same problem :out of the borderplace(but dont have
> >    border) the colors is confused.
> > actually i think ,in vector map the border is a
> continuse
> >    of end of contours line(related to digitizing)..
> > Regards
> > Ramin
> > ---
> >  Moritz Lennert <mlennert at club.worldonline.be> wrote:
> > > Ramin Safa said:
> > > > hi Moritz
> > > > thanks ,i did v.transfom.
> > >
> > > And did it work correctly ? Have you checked with
> > > d.what.vect to see the
> > > resulting attribute values ?
> > >
> > > > but now please go to problem
> > > no:737<grasslist>r.slop.aspect
> > >
> > > I've seen your mail, but can't answer your question
> > > without more
> > > information about your data. On what file did you run
> > > r.slope.aspect ?
> > >
> > > > the answers is not real and not correct.
> > >
> > > Then probably the data is not correct.
> > >
> > > > r. report also is no correct.
> > >
> > > idem
> > >
> > > > i dont know why.
> > >
> > > One reason might be that your contours were actually
> > > digitized as areas,
> > > not as lines. You might want to try by transforming
> all
> > > the areas to lines
> > > (you could use v.area2line). After the transformation
> you
> > > would have to go
> > > into v.digit and lable the lines, but seen that you
> don't
> > > have too many of
> > > them, this shouldn't be too much work. Then you could
> use
> > > v.surf.rst or
> > > something like that.
> > >
> > > Moritz
> >
> > __________________________________
> > Do you Yahoo!?
> > Yahoo! SiteBuilder - Free, easy-to-use web site design
> software
> > http://sitebuilder.yahoo.com
> 
> --
> -------------
> Ing.  Massimiliano Cannata
> Istituto di Scienze della Terra - SUPSI
> C.P. 72 - CH-6952 Canobbio (Ticino, Switzerland)
> Tel +41 91 /935 12 25 - Fax +41 91 /935 12 09
> eMail: massimiliano.cannata at ist.supsi.ch
> Internet: http://www.ist.supsi.ch
> 


=====

Ramin Safamanesh 
Department of  Environment Science , UPM
Email :  rsafamanesh at hotmail.com Tel  :  0060122399448  


__________________________________
Do you Yahoo!?
Yahoo! SiteBuilder - Free, easy-to-use web site design software
http://sitebuilder.yahoo.com